1. Field of the Invention
The present invention relates generally to a cassette reel suitable for use with, for example, a video cassette. More particularly, this invention relates to a cassette reel having an indicator for a tape volume on its upper flange.
2. Description of the Prior Art
So far there have been proposed various tape cassette reels for use with a video cassette. FIGS. 1 and 2 illustrate an example of the conventional tape cassette reel. FIG. 1 is a perspective view of the cassette reel and FIG. 2 is a cross-sectional view taken along a line II--II in FIG. 1.
Referring to FIGS. 1 and 2, there is shown a tape cassette reel 13 that comprises a hub 1 integrally molded with a lower flange 2 and an upper flange 3 fixed to the upper end face of the hub 1. The upper flange 3 is formed of a transparent plastic plate and has projections 5, . . . 5 protruded downwards from a stepped portion 4 of the lower surface thereof as shown in FIG. 2. Thus, when these projections 5, . . . 5 are welded on an upper end face 6 of the hub 1 by ultrasonic welding process, the upper flange 3 is fixed to the upper end face 6 of the hub 1. The upper flange 3 forms on its upper surface a concave portion 7 in correspondence with the hub 1. The shape of the concaved portion 7 is circular and the diameter thereof is slightly smaller than that of the hub 1. The circular concave portion 7 forms at its center an opening portion 8. A center pin 9, which forms a contact portion with a cassette reel pressing spring provided on a video cassette housing, is loosely held between the central lower surface of the upper flange 3 and the central upper end face of the hub 1. The hub 1 is provided on its lower surface with a hub drive shaft engaging opening 10 that is engaged with a hub drive shaft (not shown) provided on the main body of the video tape recorder. Also, the hub 1 is provided around its peripheral surface with a clamp piece engaging portion 11. This clamp piece engaging portion 11 serves to fix a tape end of a video tape in cooperation with a clamp piece (not shown). While, around its outer peripheral surface of the lower flange 2 there is formed a gear portion 12 that engages with a reel brake (not shown). Further, there are provided indicators 18 and 19 on the upper surface of the transparent flange 3 by which the user can check the tape volume. The indicator 18 is formed of a plurality of wrinkled or crimped portions, for example, five crimped portions 18a, 18b, 18c, 18d and 18e aligned in the diametrical direction of the upper flange 3. While, the indicator 19 is formed of five crimped portions 19a, 19b, 19c, 19d and 19e similarly arranged on the upper surface of the upper transparent flange 3.
FIG. 3 shows an example of a video cassette having the thus arranged cassette reels 13, 13 accommodated therein. In this embodiment, as shown in FIG. 3, this video cassette comprises a housing 14, and the housing 14 has on its upper surface a window 15 made of transparent plastics. Through this transparent window 15, the user can check the volume of a tape 16 that is extended between the cassette reels 13, 13. In other words, the transparent window 15 enable the user to check the consumed and/or remaining volume of the tape 16. There are provided the above-mentioned cassette reel pressing springs 17, 17 which hold the cassette reels 13, 13, respectively.
Incidentally, a plurality of cassette reels 13 are usually stacked up and transported at the manufacturing stage when the cassette reels 13 are assembled into the video cassette. At that time, the lower flange 2 of another cassette reel 13 collides with the transparent upper flange 3 of one cassette reel 13 so that the transparent portion of the upper flange 3 of the latter cassette reel 13 is damaged by the lower flange 2 of the former cassette reel 13.
In order to protect the transparent portion of the upper flange of the cassette reel from being damaged when the cassette reels are stacked and transported for assembly, a cassette reel is proposed to have projections formed on the outer surface of the upper flange and protruded outwardly (see Japanese Laid-Open Utility Model Application No. 55-144681). In the thus proposed cassette reel having the projections formed on the outer surface of the upper flange, these projections are fully exposed to view through the transparent window of the video cassette. Also, these projections are designed awkwardly and the appearance of the video cassette is made unattractive, thus degrading the value of the video cassette as a product.